<body>
    <div id="test"></div>
    <script src="https://unpkg.com/react@16/umd/react.development.js" crossorigin></script>
    <script src="https://unpkg.com/react-dom@16/umd/react-dom.development.js" crossorigin></script>
    <script>
        const e = React.createElement;
        const el = e(
            'button',
            { onClick: () => console.log('=======') },
            'Like'
        );
        ReactDOM.render(el, document.getElementById('test'));
    </script>
</body>